A wide variety of processes have been employed in the past to produce a raised embossed effect on substrates in general and fiber board ceiling panels in particular. One such prior method includes pressing a textured roll or plate onto the surface of the substrate. Another prior method includes cutting, abrading, or routing out a portion of the surface of the substrate, thus creating a pattern. Yet another prior method includes application of a pattern from a printing press employing an adhesive ink followed by building up the pattern with solid material which is attached to the inked portion. Still another prior process includes the use of a chemical ink which resists cutting action followed by abrading of the surface. In an additional prior process a template having a pattern therein is placed over the surface. Those portions of the substrate not shielded by the template are then cut or abraded away.
The above prior methods suffer from a number of disadvantages. In general, the substrate is weakened because of the portion of the substrate material removed. Another disadvantage is that cutting, routing, and abrading creates dust. The dust creates an explosion hazard and is hazardous to workers. In order to ameliorate these hazards it is necessary to install and maintain complicated and expensive dust collection systems. Furthermore, when adhesive links are employed the material attached to the ink is flammable and difficult to handle.
Accordingly, it is an object of the present invention to provide an improved process for producing a raised embossed effect which is substantially free of one or more of the disadvantages of prior processes.
Another object is to provide an improved process which does not weaken the substrate.
Yet another object is to provide an improved process which does not require cutting, routing, or abrading.
Still another object is to provide an improved process which does not require the use of adhesive inks, chemical inks, or templates.
Additional objects and advantages of the present invention will be apparent to those skilled in the art by reference to the following detailed description and drawing which is a schematic representation to no scale of an apparatus suitable for practicing the process of the present invention.